The 2018 Formula 1 World Championship grid is finally complete. Williams Martini Racing has confirmed former GP2 Series race-winner Sergey Sirotkin will be Lance Stroll’s teammate, while former Grand Prix winner Robert Kubica will return to the sport as the team’s test and reserve driver.

Sirotkin emerged the winner in a shootout with Kubica to be Stroll’s teammate in a head-to-head series contest with the Polish driver whose F1 career looked to be finished when his right arm was almost amputated in a rally crash in the 2011 off-season.

Sirotkin has been backed by SMP Racing, a Russian-based programme that develops local drivers from karting through the top ranks of motorsport. He finished an impressive third overall in his rookie season of GP2 Series racing in 2015 and repeated the feat in 2016 while also serving as a test driver with the Renault Sport F1 team. In 2017 he was promoted to a reserve driver role and took part in four FP1 outings as well as the Bahrain tyre test.

“To say I’m happy and proud to join such a famous team like Williams is an understatement,” Sirotkin said.

“It took a huge amount of work to get where I am, and I’m really happy and thankful to everyone involved. The result of our combined efforts has helped me achieve my dream, and rest assured the team can rely on me to deliver my best.”

It is no secret that Stroll and Sirotkin are armed with multi-million-dollar sponsorship portfolios, helping Sirotkin outgun the likes of reserve driver Paul di Resta and potentially even Kubica. The stories from the Bahrain end-of-year shootout were that Kubica did not outperform Sirotkin to merit selection in their 2018 race line-up, although that could also be Williams trying to avoid accusations that their driver selection decisions are more swayed by money than ability.

The Grove team is trying to signal a return to its raison d’être of investing in engineering ahead of drivers with the goal of developing such outstanding cars that it will have a huge list of top-line drivers offering their services at rock-bottom retainers.

As Williams has slipped down the Constructors’ Championship standings behind fellow privateers and Mercedes customers Force India, it is clear that the team needs more money, particularly if the likes of McLaren-Renault and the Renault factory team are expected to be more competitive in 2018.

The team’s new Chief Technical Officer, Paddy Lowe (formerly of Mercedes), is charged with rebuilding the team’s engineering resources and to return the team to frontrunning competitiveness. The income from its two drivers, offset against a reduction in the team’s prizemoney for poor 2016 and 2017 seasons, will help.

Sirotkin’s finances – a reported $22 million a year – are guaranteed to the point of his deal with Williams being “multi-year”, but the delays in confirming him might have been due to Williams’ sponsorship team having to smooth over concerns that may have been raised among its existing sponsor portfolio.

The Russian’s backers, SMP Bank, is on the blacklist of organisations sanctioned by the United States and Canada – but not the European Union – stemming from the Crimean crisis in 2014. The bank is owned by Boris and Arkady Rotenberg, who both have a very close relationship with Russian president Vladimir Putin.

Departing somewhat from the use of its test and reserve drivers, Williams will run Kubica in a number of Friday practice sessions at selected Grands Prix in addition to the pre-season tests at Barcelona and during in-season testing to help develop the new FW41 chassis.

“I’m extremely happy to be joining the Williams team as its official Reserve and Development Driver this season,” Kubica said.

Kubica will make a popular return to the F1 paddock.

“I feel in the best physical shape that I have ever been, but it has taken a lot of work to get to where I am now, so I’d like to thank Williams for the opportunities they have given me so far, and for putting their faith in me with this appointment.

“I have enjoyed being back in the Formula One paddock over these past few months, and I now look forward to working with the Williams technical team, both at the factory and at the track, to really help push forward the development of the FW41 and to make a real difference to their 2018 campaign.

“Having driven both the FW36 and the FW40, I’m looking forward to seeing how the FW41 measures up on track and working with the team to ensure we can maximise the performance of the car. My ultimate goal remains to race again in Formula One and this is another important step in that direction: I cannot wait to get started.”